Adapter plug for electric outlets



Ocl- 20 1942- c. G. ElsEiNBERG` JR ADAPTER PLUG FOR ELECTRIC OUTLETSPatented Oct. 20, 1942 UNITED STATES ADAPTER PLUG FOR ELECTREC OUTLETSCharles G. Eisenberg, Jr., Wauwatosa, Wis. Application August 4, 194.1,Scriai No. 435,334

6 Claims.

for the reception of two appliance plugs, each plug having a pair ofconductor prongs. Frequently, however, it is necessary or desirable toconnect more than two electrical devices to a wall plate. In such caseit is customary to utilize l an adapter plug popularly termed a cubetap, which has a pair of prongs received in one of the sets of femaleopenings in the wall and which provides three outlets positioned at thefront,

top, and bottom of the adapter and all electrically connected with theone pair ci prongs entering said female openings. While this type ofadapter provides ample facilities for the connection of additionalappliance cords to a single wall plate, nevertheless it has been foundvery unsatisfactory in use. The three-cord sets attached to a singlecube tap, which cords are often rendered heavy by a rubber coating,exert a substantial downward and outward pull on the adapter which isgreater than the resistance offered by the friction between the singlepair of closely positioned prongs and the yielding contacts within thefemale wall fitting. Inasmuch as the single pair of closely positionedprongs affords the sole means of support for the threeway adapter andfor the plugs and cords connected thereto, these adapter plugs of thecube tap type are continually being either pulled co1.-- pletely out ofthe sockets or are so weighted down by the cord assemblies as to assumea downwardly inclined and nearly pulledmut position. When in thisposition poor electrical contact is provided. and the slightest jerk onone of the cords will disengage the adapter and cause it to fall to thefloor.

It is one of the obiects of the present invention to provide a unitaryadapter plug for use with wall plates having two spaced sets of socketopenings, Which adapter is specially constructed to simultaneouslycooperate with both sets of openings to the end that it is rigidlysupported against downward and outward strains. As a result, a pluralityof plug and cord sets may be safely connected to the adapter withoutcausing loosening or disengagement thereof. Furthermore, the connectionbetween the adapter and the wall will withstand the usual pullingstrains to which a plug is subjected.

A further more specific object of the invention 5 is to provide anadapter including a unitary elongated body of a length to overlap bothsets of openings in a standard double wall plate wherein there is a pairof prongs near one end of the body for cooperation with one Vset of wallplate openings and a pair of prongs near the other end of the body forsimultaneous cooperation with the other set oi wall plate openings tothereby aiiord a four-point support comprising two widely spaced groups.

A further object of the invention to provide a construction as abovedescribed wherein the contact fingers within the adapter are so arrangedand connected as to permit the provision of two outlets on each side ofthe adapter body and of two outlets on the front of the adapter body.

With the above and other objects in view, the invention consists of theimproved adapter plug and all its parts and combinations as set forth inthe claims, and all equivalents thereof. In

the accompanying drawing, in v hich the same y reference numeralsdesignate the same parts in all of the views,

Fig. l is a front elevational View showing the improved adapterconnected to a wall plate;

Fig. 2 a side elevational view, part being shown in vertical section;

Fig. 3 is a sectional View through the plug alone taken on the line 3 3of 2; and

Fig. 4 is perspective view showing the improved adapter about to beinserted in the outlet opening ci a wall plate.

Referrin `more particularly to the drawing, the numeral. designates awall plate of a standard type now in use having longitudinally spacedopenings B and 'l embracing outlet ttings 8 and 9. These outlet iittingsare electrically connected with a source of electricity, the fitting 8includes a pair of openings @El which extend longitudinally of the wallplate and which guide the prongs of a plug into electrical Contact withthe usual Contact fingers within the outlet f1tting. The outlet fitting2 is with similar outlet openings ll.

The improved adapter plug may be formed of electL insulating material.such as one of the compositions of which Bakelite is an example, rubber,or other suitahle substance. it comprises elongated body i2 ci a lengthto overlap both of the oi/let ttings il and 9 in a standard wall plate.

The upper half of the body is provided with plug receiving or outletopenings i3 in front, lf3 on one side. and l5 on the opposite side, Iandthe lower half of the body provides similarly arranged outlet openingsdesignated by the same numerals. Referring to Fig. 3, there is ayielding contact finger IB adapted to be engaged by a prong entering theuppermost front opening i3, and said finger has a reversely bent angularportion Il, as illustrated in Fig. 2, so that good electrical contact isprovided. A double-ended iinger I8 crosses the inner end of the finger tand has one end inwardly bent in the saine manner as the bend l1 of thefinger IB and cooperable with the uppermost side opening l5 of the bodyand its other end similarly bent and cooperable with the uppermost sideopening lli of the body. The two crossed finger forming members areconnected to the inner end I9 of a prong 22, and said prong extendslaterally and downwardly within the body as at 2l, and it is thentwisted to right angles as at 22 so that the portion of the prong 25!which projects externally of the plug will have its face in a verticalplane to cooperate with one of the outlet openings le in the wall plate.

Contact iingers 23 and 2d, which are formed in the same manner as thecontact iingers i6 and I8 respectively, are positioned to coact with thelower of the top sets of openings i3, ld, and l5, and said fingers areelectrically connected with the inner end 25 of a prong 2%. Internallyof the body the prong 26 is bent laterally and upwardly, as at 2l, andis then twisted so that the external portion of the prong 26 is parallelto and in horizontal alinernent with the prong 22. It is thereforeapparent that the prong 2! makes electrical connection with the upperprongs of' appliance plugs 2S, 29, and 2S when said plugs are insertedin the adapter tting as shown in Fig. d, and that the prong 2S makeselectrical connection within the adapter with the other prongs ofappliance plugs 2E, 29 and Sii.

Within the lower half of the body the arrangement is identical as thatdescribed in connection with the upper half, and the lower prongs 3l and32 are electrically connected within the body to the prongs of lowerappliance plugs 33, 34 and 35 when said prongs are inserted in themanner shown in Fig. 4 in the lower sets of openings I3, I4, and I5 ofthe adapter.

It is apparent from the above arrangement that in a single unitary bodywhich is of a length to overlap both of the outlet ttings 8 and 9 of astandard wall plate, there is one set of prongs and near one end of theadapter body l2 and another pair of prongs 3l and 32 spaced asubstantial distance from the prongs 20 and 2S. This spacing coincideswith the standard spacing between the outlet openings I in the standardwall plate 5 and the outlet openings Il therein. Thus, a single unitarytting coacts simultaneously with both sets of outlet openings in thewall plate as shown in Figs. 2 and 4 to furnish rm support.

Because of the wide spacing between the prongs 20, 26 and 3 l 32 theweight of the appliance plugs 28, 29, 32, 33, 3d, and 35 plus the weightof the cords 35, 3l, 3d, 39, lill, and il will not tend to loosen theadapter from its rrn connection as shown in Fig. 2 and will not tend topull the adapter to an outwardly and downwardly inclined position ascommonly takes place when a threeway cube tap is used, which type ofadapter iitting has its sole support furnished by one pair of prongs. Inaddition, the firm support provided by the improved construction of thepresent adapter fitting enables the adapter to withstand the usualrninor jerks on the appliance cords.

While the invention has been shown for use in connection with doublewire electrical systems, it is obviously applicable for use inconnection with outlet plates as used in three-wire circuits, whereinthere are three openings corresponding to the openings l and threeopenings corresponding to the openings H. In such cas-e there would bean additional prong grouped with the prongs 2), 26 and an additionalprong grouped with the prongs 3l, 32 and of course the outlet openingsin the adapter would be in sets of three instead of in sets of two.

The broad concept of the invention is the use of a unitary body of asize to overlap a plurality of outlet ttings in a single wall plateassembly, with the adapter provided with a plurality of widely spacedsets of prongs to furnish drm support against forces which tend to causedisengagement of the adapter from the wall plate.

Various changes and modications may be made without departing from thespirit of the invention and all of said changes are contemplated as maycome within the scope of the claims.

What I claim is:

1. An adapter plug comprising a unitary body, a plurality of sets ofexternal pron-gs extending into said body, said prongs having projectingends constructed and arranged for quick insertion in the prong receivingopenings of standard outlet fittings and the individual prongs in eachset being electrically separated from each other, and a plurality ofcontact fingers within the body in electrical connection with each setof prongs, said adapter body having a plurality of sets of outletopenings for guiding the prongs of appliance plugs into electricalContact with said ngers, said sets of external prongs being widelyspaced to furnish cooperative support against loosening or disengagementof either set of prongs of the adapter from electric outlet ttings withwhich said prongs are adapted to simultaneously engage.

2. An adapter plug comprising a unitary body, a plurality of sets ofexternal prongs extending into said body, said prongs having projectingends constructed and arranged for quick insertion in the prong receivingopenings of standard outlet nttings and the individual prongs in eachset being electrically separated from each other, and a plurality ofconta-ct ngers within the body in electrical connection with each set ofprongs, said adapter body having a plurality of sets of outlet openingsfor guiding the prongs of appliance plugs into electrical contact withsaid iingers, said sets of external prongs being spaced apart a distanceequal to the spacing between the outlet littings of a standard pluraloutlet wall lixture to simultaneously engage the plurality of ttingstherein, and said sets of prongs furnishing cooperative support againstloosening or disengagement of either set.

3. An adapter plug comprising an elongated unitary body, a set oiexternal prongs extending into said body adjacent one end of the latter,a set of external prongs extending into the body adjacent its oppositeend, said prongs having projecting ends constructed and arranged forquick insertion in the prong receiving openings of standard outletttings and the individual prongs in each set being electricallyseparated from each other, and a plurality of contact iingers within thebody in electrical connection with each set of prongs, said adapter bodyhaving a group of side and front outlet openings for each set ofexternal prongs 'for guiding the prongs of appliance plugs intoelectrical connection with the Contact fingers for each set of prongs ofthe adapter, said sets of external prongs of the adapter being widelyspaced to furnish cooperative support against loosening `ordisengagement of either set of prongs of the adapter from electricoutlet fittings with which said prongs are adapted to simultaneouslyengage.

4. An adapter plug comprising an elongated unitary body, a set ofexternal prongs extending into said body adjacent one end of the latter,a set of external prongs extending into the body adjacent its oppositeend, said prongs having projecting ends constructed and arranged forquick insertion in the prong receiving openings of standard outletiittings and the individual prongs in each set being electricallyseparated from each other, and a plurality of contact fingers within thebody in electrical connection with each set of prongs, said adapter bodyhaving a group of side and front elongated outlet openings extending ina direction transversely of the body for each set of external prongs ofthe adapter, said openings in the adapter being adapted to guide theprongs of appliance plugs into electrical connection with the contactlingers for each set of prongs of the adapter, said sets of externalprongs having faces in planes extending longitudinally of the body andthe sets being widely spaced to furnish cooperative support againstloosening or disengagement of either set of prongs of the adapter fromelectric outlet ttings with which said prongs are adapted tosimultaneously engage.

5. In combination, an electric wall fixture having two spaced outletttings therein each provided with a plurality of prong receivingopenings, a unitary adapter including a body of a size to overlap bothof said outlet ttings, two sets of external prongs extending into saidadapter body, one set of prongs being removably engaged in the prongreceiving openings of one outlet ntting and the other set beingremovably engaged in the prong receiving openings of the other outletfitting, and a plurality of contact lingers within the body inelectrical connection With each set of prongs, said adapter body havinga plurality of sets of outlet openings for guiding the prongs ofappliance plugs into electrical conta-ct with said iingers, said sets ofexternal prongs being Widely spaced to furnish cooperative supportagainst loosening or disengagement of either set of prongs of theadapter from the prong receiving openings in said electric outletfittings.

6. In combination, an electric Wall fixture having two spaced outletfittings therein each provided with a plurality of prong receivingopenings, a, unitary adapter including an elongated body of a length tooverlap both of said outlet fittings, a set of external prongs extendinginto said body adjacent one end of the latter, a set of external prongsextending into the body adjacent its opposite end, one set of prongsbeing removably engaged in the prong receiving openings of one outletiitting and the other set of prongs being removably engaged in the prongreceiving openings of the other outlet iitting, and a plurality ofcontact ngers within the body in electrical connection with each set ofprongs, said adapter body having a group of side and front outletopenings for each set of external prongs of the adapter for guiding theprongs of appliance plugs into electrical connection with the contactfingers, said sets of external prongs being widely spaced t0 furnishcooperative support against loosening or disengagement of either set ofprongs of the adapter from the prong receiVing openings of the electricoutlet fittings.

CHARLES G. EISENBERG, JR.

